Carburetor detergent and corrosion inhibiting motor fuel compositions

ABSTRACT

Motor fuel composition comprising a mixture of hydrocarbons in the gasoline boiling range containing an aliphatic hydrocarbon substituted succinamic acid represented by the formula:   IN WHICH R is an aliphatic hydrocarbon radical having from about 12 to 20 carbon atoms, and X and Y alternately represent hydrogen and an aliphatic hydrocarbon radical having from 6 to 16 carbon atoms.

United States Patent Dorn Sept. 16, 1975 l l CARBURETOR DETERGENT AND Primary Examiner-Patrick P. Garvin CORROSION INHIBITING MOTOR FUEL ASSl'SmnI in rAndreW H- M tz COMPOSITIONS Attorney, Agent, or FirmT. H. Whaley; C. G. Ries; J.

J. 01. b1 [75] Inventor: Peter Dorn, Lagrangeville, NY. Oug m [73] Assignee: Texaco Inc., New York, NY. [57] ABSTRACT [22] File Oct. 30, 1972 Motor fuel composition comptising a mixture of hydrocarbons 1n the gasoline boiling range containing an PP 301,905 aliphatic hydrocarbon substituted succinamic acid represented by the formula:

[52] US. Cl. 44/71; 44/62; 44/80 51 Int. Cl c101 1/22 9 581 Field of Search 44/62, 71, 80

l [56] References Cited UNITED STATES PATENTS 3,031,282 4/ 1962 Andress et al. 44/71 in which R i an aliphatic hydrocarbon radical having f from about 12 to 20 carbon atoms, and X and Y alterooreea. 3 672 852 6/1972 Vermillion et al... 44/62 {l 59 f g i a 3,676,089 7 1972 Morris etal. 44/62 mm o on 14 Claims, No Drawings CARBURETOR DETERGENT AND CORROSION INI-IIBITING MOTORFUEL COMPOSITIONS BACKGROUND OF THE INVENTION 1. Field of the Invention Modern internal combustion engine design is undergoing important changes to meet new federal standards concerning engine exhaust gas emissions. A major change in engine design recently adopted is the feeding of blowby gases from the crankcase zone of the engine into the intake air supply to the carburetor rather than venting these gases to the atmosphere as inthe past. Further changes being adopted involve the recycling of a part of the exhaust to the combustion zone of thc en gine in order to further reduce objectionable emissions. The recycled exhaust gases contain substantial amounts of deposit-forming substances which promote the formation of deposits in and around the throttle plate area of the carburetor. These depositsrcstrict the flow of air through the carburetor at idle and at low speeds so that an overrich fuel mixture results. This condition produces rough'engine idling and stalling, and serves to increase the undesirable exhaust emissions whichthe engine design changes are intended to overcome.

Modern gasoline compositions are vcry highly re fined products. Despite this. they contain minor amounts of impurities which can promote c'cirrosion during the period that the fuel is transported and stored, and even in the'fuel tank, fuel lines and'carburetor of the motor vehicle. An' acceptable hioto'r fuel must contain a corrosion inhibitor to inhibit or prevent corrosion. I l I I I i i inzwhich R is an aliphatic hydrocarbon radical having from about 12 to 20 carbon atoms and X and Y alternately represent hydrogen and an aliphatic hydrocarbon'radicalhaving from about '6 to T6 carbonmbms. Both aliphatic hydrocarbon radicals can be saturated. in a preferred-erp bodih'ient of the invention, X orY is an alkenyl radical having from about? to 14 carbon atoms. R is preferably a saturated aliphatic radical having from 'lo jto [8 carbon atoms. I I II Methods forvpr e p'aringthc additive or theiinvention are well ,know nanddo'not constitute of this invention. in a preferred method, an olefinically unsaturated hydrocarbon is'rea'cted with mal'eic anhydride to produce an alkeny l lsuccinic anhydride. This is the n'reacted with an aliphatic arnine of suitable chain length in. to 1 mole proportionsv at a temperature below about 95C. to produce an N-alkylalkenyl-succinzimic acid. lt will be appreciatcd that the product can be a mixture of compounds conforming to the alternate versions of the formula given .above. It also be under stoodthat the miitture of compounds can effectively be employed as the additive in the motor fuel of the invention. I The following example is typical pfhthe preferred method for preparing the additive; L

EXAMPLE I N l'allow Tetrapropenyl succinamic Acid I 0.7 equivalent of tallow a'mine 179 of a'commercial tallow amine-Arniecn- 'I and i).7 equivalent 186 g.) tctrapropeiiyl succinic'anhydridc and 365 gm. of ity lehe are heated with gehtlestirring at about 80C. for approximately 6 hours. 'lhe recoveryi fquanti tativei 2. Summary of the Invention" i i 35 730 of an amber fluid oil. y l I A class of aliphatic hydrocarbon substituted suc'ci A t i al ly i m hi a i f w namic acid compounds are provided as carburetor detergcnts and corrosion inhibitors when employed in a liquid hydrocarbon fuel for an internal combustion engine. These compounds. which are characterized h5g 1.0 having two relatively long hydrocarbon radicals, ineluding one attached to a nitrogen atom, appear to be N,,'*'" 4q unique in their carburetor detergcncy and corrosion f'i "3x33 inhibiting properties. Similar compounds having addi- 4 tional hvdro hilic rou s are susceptible to extractionby the tank Jvater bott ms present in fuel distribution v I T u j l ilfcfffcbttlve llddlllves systems making it difficult to maintain an effective-con m if mf fuel p i n of the invention: centration of the additive in the fuel composition. T Q Tctmpmpcllyl Succmamlc Acld The fuel composition of the invention prevents or w i f-"E mitigates the problems of corrosion and deposits 'la'y q l l Sucumlmlc Acld down in the carburetor of an internal combustion. en- 'Cm-F'zu Alkyl retrllpmpbnyl Succmllmlc Alld ginc. When a gasoline of the invention is employed in (dcr1vcd m Armcm L45) a carburetor which already has a substantial build-up of N -S I: tert. Alkyl Tetrapropenyl Succinamic Acid (dcdeposits from prior operations. a rather severe test of' ff' from pnmcncyiil-k) i the detergency property ola fuel composition, this gas '1 m- :2 Alkyl p p succmllmlc Acid olinc is very effective for removing substantial amounts Q Y m P m i of the pre-formcd deposits. I I I I I N- Tallmv Dodecyl 's uc cinamic" Acid i I I I I N-Oleyl Dodecyl Succinaniic Acid oiascRl 'iioN or 'l'Hl'I PRraFE-RRF- N-(lg-t'gl. Sc'c. .All'tyl Dotlecyl succinaniic 'At-id' i EMBQD'MENTS v .N-(y tcrt. Alkyl outlet- 1 Succinamie Acid The aliphatic hydrocarbon substituteds uccina mic IAIIIITCI P Q b U iph hy d f Subktitllmd acid of the invention is represented by the formula: SILIQQIIRIITIUIQZICILI"f l E f Ihe mpl yed n I I I v I; 1! l thegasoline fuel composition in a concentration both It I M to.provideieffcctive carburetor'dete rgency and corro- I sion 'inhibiting pr'o'pciti'cs. In general? the additive is I I employed iii a concentration ranging from about Y-CH-COOH 4 ()()5 to ..l weight percent with'a preferred concen- 3 tration' ranging from about 0.002 to 0.075 weight percent. 1

'Anypga'so line suitable fora spark-ignited; internal combustion engine can be used in the practice of this invention. In general. the base fuel will-consist of a mix- The prescribcd aliphatic hydrocarbon substituted succinamic acid additive was tested for effectiveness in the carburetor dctergency test. This test is run on a Chevrolet V-8 engine mounted ona' test stand using a modified four-barrel carburetor The two secondary barrels of the carburetor are sealed and the feed to each of the primary barrels arranged so that the detergent additive fuel can run in one barrel and the reference fuel run in the other. The primary carburetor barrels were also modified to contain removable aluminum inserts in the throttle plate area v so that the deposits formed on the inserts could be conveniently weighted.

Two, procedures were used to determine the effectiveness of additive fuel for removing preformed deposits in the carburetor. In the first procedure. designated l, the engine is run for a period of time, usually 24 to 48 hours. using thebase fuel as the feed to both barrels with engine blowby circulated to the airinlct of the carburetor. The weight of the deposits on both sleeves fuel and of the additive fuels for removing deposits expressed'in'percent. I

In the second procedure. designated II, the engine is run.for a period of time. usually 24 to 48 hours. using 5 the base fuel as the feed to both barrels with engine blow-by circulated to the air inlet of the carburetor. The weight of the deposits on both slecves is deter- "mined and recorded. The engine is then cycled for 24 additional hours with base fuel being fed to one barrel and the additive fuel to the other. During the cycle. engine blow-by is circulated 'to the air inlet of the carburetor. The inserts are than removed from the carburetor and weighted to determine the difference between the performances of the additive and detergent fuels for removing preformed deposits. After the aluminum inserts have been cleaned, they are replaced in the carburetor and the process repeated with the fuel feeds into the carburetor reversed in order to minimize differences in fuel distribution and carburetor construction. The re sults obtained in the two runs are averaged and the effectiveness of the base fuel and of the additive fuels for removing deposits expressed in percent.

The base fuel employed in the following examples was a premium grade gasoline having a Research Octane Number of about 100 and containing 3 cc. of tetraethyl lead per gallon. This gasoline consisted of about 25 percentaromatic hydrocarbons l0 percent olefinic hydrocarbons and 65 percent paraffinic hydrocarbons and boiled in the range from about 90fF. to 380F.

Fuel compositions of the invention were tested in the Chevrolet Carburetor Detergent Test and the results set forth in Table 1 below. The percent effectiveness reported is the difference obtained by subtracting the percent effectiveness of the base fuel from the percent effectiveness of the additive fuel.

TABLE! CARBURETOR DETERGENCY TEST Wash oawa '2 (3 l l PH! Additive concentration in pounds per thousand barrels of gasoline.

I2) Addithc fuel contained (1.075 vol. percent of pol \prop \lcnc of about 850 aver. mol. weight and (H2 vol. percent of petroleum carrier oil. 4

U) sign indicates fuel hniltup dc wsits.

I4) Additive also contains an equal weight of sylcnc.

is determined and recorded. The engine is then cycled for 24 additional hours with base fuel being fed to one barrel and the additive fuel to the other and no blow by to the carburetor air inlet. The inserts are then removed from the carburetor and weighed to determine the difference between the performances of the additive and non-additive fuels for removing preformed deposits. Aftcr the aluminum inserts have been cleaned. they are replaced in the carburetor and the process rcpcatcd with the fuel'feeds into the carburetor reversed in order to minimize differences in fuel distribution and carburetor construction. The results obtained in the two runs are averaged and the effectiveness of the base The corrosion inhibiting properties of a gasoline composition of the invention was determined in a corrosion test designated the Colonial Pipeline Rust Test. In this test. a steel specimen, polished with nonwaterproof fine emery paper is immersed in 300 ml of stirred test fuel at 100F. for 30 min. Then 30 ml distilled water is added and stirred for 3.5 hours. The specimen is visually rated and a rating of 57( rust is considered passing.

The Base Fuel employed in this test is identical to the Base Fuel used in the Examples of Table l above. The

results are given in the Table below:

TABLE 11 Additive also contains an e ual amount ofxylenc.

It is evident from the foregoing data that the novel aliphatic hydrocarbon substituted succinamic acids of the invention are outstandingly effective as rust or corrosion inhibitors in gasoline.

The fuels of the invention may contain any additive conventionally employed in gasoline. 'l'etraalkyl lead. antiknock additives. dyes. corrosion inhibitors, antioxidants and the like can be beneficially employed without materially affecting the detergent additive of the invention. (lasolines containing from about 0.01 to 0.20 volume percent of a polymer, copolymer or the corresponding hydrogenated polymer or copolymer of 11C; to C unsaturated hydrocarbon having a molecular weight in the range of 500 to 3.500. preferably from 650 to 2.600. as described in 1.1.5. Pat. No. 3.502.451. which disclosure is incorporated in this application. in combination with the detergent of the present invention are particularly effective multifunctional fuels. compositions containing polypropylene and polyisobutylene of N00 to 1.100 molecular weight at from about 0.025 to 0.1 volume percent being particularly prefcrred.

1 claim:

1. A motor fuel composition comprising a mixture of hydrocarbons in the gasoline boiling range containing from about 00005 to 0. 1 weight percent of an alkenyl succinamic acid represented by the formula:

X-CH-C-NH-R Y-CH-COOH in which R is an aliphatic hydrocarbon radical having from about 12 to 20 carbon atoms and X and Y alter- (ill nately represent hydrogen and an aliphatic hydrocarbon radical having from about 6 to 16 carbon atoms.

2. A motor fuel composition according to claim 1 in which R is an essentially saturated aliphatic hydrocarbon radical.

3. A motor fuel composition according to claim 1 in which R consists predominantly ofC and C aliphatic hydrocarbon radicals.

4. A motor fuel composition according to claim 1 in which X or Y is an aliphatic hydrocarbon radical having from about 8 to 14 carbon atoms.

5. A motor fuel composition according to claim 1 in which X or Y is an alkenyl radical.

6. A motor fuel composition according to claim 1 in which X or Y is a tetrapropenyl radical.

7. A motor fuel composition according to claim 1 in which R is an octadecyl radical.

8. A motor fuel composition according to claim 1 in which R is an octadeccnyl radical.

9. A motor fuel composition according to claim 1 in which R is a tetradecyl radical.

10. A motor fuel composition according to claim 1 containing from about 0.002 to 0.075 weight percent of said alkenyl succinamic acid.

ll. A motor fuel composition according to claim 1 containing from about 0.01 to 0.20 volume percent of l a polymer of C to C unsaturated hydrocarbon 3 1 a copolymer of a C to C unsaturated hydrocarbon. or (3) the corresponding hydrogenated polymer or copolymer. said polymer or copolymer having a molecular weight in the range from about 500 to 3.500.

12. A motor fuel composition according to claim 1 containing from about 0.025 to 0.1 volume percent of polypropylene having a molecular weight ranging from about 800 to 1.100.

13. A motor fuel composition according to claim 1 containing from about 0.025 to 0.1 volume percent of poly-'isobutylene having a molecular weight ranging from about 800 to 1.100.

H. A method for preventing the build-up of carburetor deposits in an internal combustion gasoline engine which comprises supplying to and burning in said engine a motor fuel composition comprising a mixture of hydrocarbons in the gasoline boiling range containing from about 0.0005 to 0.1 weight percent of an alkcnyl succinamic acid represented by the formula:

in which R is an aliphatic hydrocarbon having from about 12 to 20 carbon atoms and X and Y alternately represent hydrogen and an aliphatic hydrocarbon radical having from about (i to 16 carbon atoms. 

1. A MOTOR FUEL COMPOSITION COMPRISING A MIXTURE OF HYDROCARBONS IN THE GASOLINE BOILING RANGE CONTAINING FROM ABOUT 0.0005 TO 0.1 WEIGHT PRESENT OF AN ALKENYL SUCCINAMIC ACID REPRESENTED BY THE FORMULA:
 2. A motor fuel composition according tO claim 1 in which R is an essentially saturated aliphatic hydrocarbon radical.
 3. A motor fuel composition according to claim 1 in which R consists predominantly of C16 and C18 aliphatic hydrocarbon radicals.
 4. A motor fuel composition according to claim 1 in which X or Y is an aliphatic hydrocarbon radical having from about 8 to 14 carbon atoms.
 5. A motor fuel composition according to claim 1 in which X or Y is an alkenyl radical.
 6. A motor fuel composition according to claim 1 in which X or Y is a tetrapropenyl radical.
 7. A motor fuel composition according to claim 1 in which R is an octadecyl radical.
 8. A motor fuel composition according to claim 1 in which R is an octadecenyl radical.
 9. A motor fuel composition according to claim 1 in which R is a tetradecyl radical.
 10. A motor fuel composition according to claim 1 containing from about 0.002 to 0.075 weight percent of said alkenyl succinamic acid.
 11. A motor fuel composition according to claim 1 containing from about 0.01 to 0.20 volume percent of (1) a polymer of C2 to C6 unsaturated hydrocarbon (2) a copolymer of a C2 to C6 unsaturated hydrocarbon, or (3) the corresponding hydrogenated polymer or copolymer, said polymer or copolymer having a molecular weight in the range from about 500 to 3,500.
 12. A motor fuel composition according to claim 1 containing from about 0.025 to 0.1 volume percent of polypropylene having a molecular weight ranging from about 800 to 1,100.
 13. A motor fuel composition according to claim 1 containing from about 0.025 to 0.1 volume percent of polyisobutylene having a molecular weight ranging from about 800 to 1,100.
 14. A METHOD FOR PREVENTING THE BUILD-UP OF CARBURETOR DEPOSITS IN AN INTERNAL COMBUSTION GASOLINE ENGINE WHICH COMPRISES SUPPLYING TO AND BURNING IN SAID ENGINE A MOTOR FUEL COMPOSITION COMPRISING A MIXTURE OF HYDROCARBONS IN THE GASOLINE BOILING RANGE CONTAINING FROM ABOUT 0.0005 TO 0.1 WEIGHT PERCENT OF AN ALKENYL SUCCINAMIC ACID REPRESENTED BY THE FORMULA: 